[meteorite-list] NASA Team Finds Riches in Meteorite Treasure Hunt (Asteroid 2008 TC3)

From: Michael Murray <mmurray_at_meteoritecentral.com>
Date: Tue, 31 Mar 2009 14:40:56 -0600
Message-ID: <EEF6FE2D-A2B5-45CA-82A1-453D2CA2925F_at_montrose.net>

This is probably old hat by now but I believe one of Mr. Jennisken's
photos is on APOD. Here is the link: <http://apod.nasa.gov/apod/ap090328.html
>
Mike

On Mar 31, 2009, at 11:36 AM, Ron Baalke wrote:

>
> http://www.jpl.nasa.gov/news/features.cfm?feature=2094
>
> NASA Team Finds Riches in Meteorite Treasure Hunt
> Jet Propulsion Laboratory
> March 30, 2009
>
> Just before dawn on Oct. 7, 2008, an SUV-sized asteroid entered
> Earth's
> atmosphere and exploded harmlessly over the Nubian Desert of northern
> Sudan. Scientists expected the asteroid, called 2008 TC3, had blown to
> dust in the resulting high-altitude fireball.
>
> What happened next excited the scientific community.
>
> Peter Jenniskens, a meteor astronomer with the SETI Institute in
> Mountain View, Calif., who works at NASA's Ames Research Center in
> Moffett Field, Calif., joined Muawia Shaddad of the University of
> Khartoum in Sudan to search for possible extraterrestrial remnants
> from
> the asteroid. A paper on their findings is featured in the March 26
> issue of the journal Nature.
>
> Now, for the first time, scientists are studying recovered celestial
> meteorites that have a definitive link with an asteroid from space.
> This
> presents the science community an unprecedented opportunity to
> interpret
> asteroid data and learn more about the origins and differentiations
> between asteroids and may provide better answers about the formation
> of
> our solar system.
>
> The asteroid was discovered by a telescope of the NASA-sponsored
> Catalina Sky Survey. Astronomers and scientists around the world
> tracked
> and scanned TC3 for 20 hours prior to its demise. This marked the
> first
> time a celestial object was located prior to entering Earth's
> atmosphere. The asteroid had a velocity of 27,700 miles per hour
> when it
> entered the atmosphere. It created a fiery trail 51 miles long before
> exploding 121,000 feet from the ground.
>
> "When Dr. Shaddad and I first arrived and started interviewing
> eyewitnesses, things looked very bleak," said Jenniskens. "They all
> described an immense explosion in the sky, but none had seen any
> material flying out of the fireball."
>
> The location and subsequent recovery was like searching for a needle
> in
> a haystack. Scientists used what they referred to as a treasure map to
> locate the meteorites. NASA's Jet Propulsion Laboratory, or JPL, in
> Pasadena, Calif., produced a chart that gave the recovery team its
> search grid and specific target area.
>
> "My work usually begins and ends with trajectories of objects in
> space,"
> said Steve Chesley, a scientist at NASA's Near-Earth Object Program
> Office at JPL. "We had accurately predicted when and where TC3 would
> enter over the Sudan. Jenniskens was asking for a map of where any
> surviving fireball fragments could have landed. That was a first for
> the
> Near-Earth Object Program Office."
>
> Armed with the treasure map, Jenniskens, Shaddad and students and
> staff
> from the University of Khartoum began their trek in the afternoon of
> Dec. 6, 2008. After a three-day search, the team had scoured 18 miles
> along Chesley's asteroid path and recovered 15 samples with a total
> mass
> 1.24 pounds. Scientists observed the meteorites to be porous, rocky
> material, rounded like a pebble, with a broken face, and very black in
> color.
>
> Jenniskens and the Khartoum team visited the site on two more
> occasions
> and collected 280 meteorites with a total mass of approximately 11
> pounds. Samples were sent for analysis to Ames, NASA's Johnson Space
> Center in Houston, the Carnegie Institution of Washington, and Fordham
> University in New York.
>
> "We certainly found a treasure," said Michael Zolensky, a cosmic
> mineralogist at Johnson. "We have never seen a meteorite on Earth
> exactly like this one because they are so fragile that they explode
> high
> in the atmosphere. The samples appear to have originated from the
> surface of the original asteroid, making them especially valuable to
> planetologists explaining the geological history of primitive bodies
> and
> planning spacecraft missions to asteroids." By measuring how asteroid
> 2008TC3 reflected sunlight in space and comparing it to how the
> meteorites found on the ground reflected sunlight, the team concluded
> that the meteorites came from the surface of an F-class asteroid in
> our
> solar system's asteroid belt. Furthermore, the team determined that
> the
> meteorite was what astronomers refer to as a polymic ureilite, in
> other
> words, a very rare and unusually fragile, dark rock.
>
> NASA's JPL manages the Near-Earth Object Office. Johnson manages the
> Astromaterials Research and Exploration Science Directorate. NASA
> detects and tracks asteroids and comets passing close to Earth
> through a
> program commonly called Spaceguard.
>
> Asteroid 2008TC3 was relatively small to most objects detected and
> tracked by Spaceguard. Scientists estimate asteroids of its size enter
> Earth's atmosphere approximately once a year, but meteorites rarely
> survive once they land because of weather and water damage as well as
> human disturbance. Scientists are astounded at the good luck that not
> only did the meteorites land in a part of the world with ideal
> conditions to preserve such cosmic artifacts, but the observatories on
> the ground were able to detect and track the asteroid's entry.
>
> For more information about NASA's Near-Earth Object office, visit:
>
> http://neo.jpl.nasa.gov
>
> For more images from 2008TC4 detection and recovery effort, visit:
>
> http://www.nasa.gov/topics/solarsystem/tc3/
>
> Media contact: DC Agle/JPL
> 818-393-9011
>
>
> Images
>
>
> Image taken by a cellphone of the contrail left by 2008 TC3 during its
> decent. Image courtesy: Shaddad
> <http://jpl.nasa.gov/images/asteroid/20090325/apod-browse.jpg>
>
> Meteorite from asteroid TC3.
> <http://www.jpl.nasa.gov/images/asteroid/20090325/tc3.jpg>
>
>
> ______________________________________________
> http://www.meteoritecentral.com
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list
Received on Tue 31 Mar 2009 04:40:56 PM PDT